In what could be a major change in Japan’s policy on aircraft carriers, the Defense Ministry is mulling a plan to buy F-35B stealth fighter jets for use on its helicopter carriers, government sources said.

The introduction of F-35Bs, which have short takeoff/vertical landing (STOVL) capability, will be useful in countering China’s growing maritime assertiveness. They are expected to bolster Japan’s ability to defend far-flung islands in the southwest, where only short runways exist, the sources said Sunday.

The move, however, is likely to trigger a backlash from China and Japan’s other neighbors because it could be viewed as contradicting Japan’s so-called “exclusively defense-oriented policy” under the pacifist Constitution.

Prime Minister Shinzo Abe’s government has altered the nation’s postwar security policy over the past few years, most notably through new security laws that largely expand the range of activities permissible by the Self-Defense Forces.